Modelling the nonlinear deformation in steel-belted radial tyres under inflation loading

A new nonlinear axisymmetric finite element model has been developed for the stress-strain analysis of pneumatic lyres. The model combines the built-in nonlinear capabilities of the commercial code COSMOS/M (NSTAR module) with tensorial calculations required to compute the stiffness properties of a cord-rubber composite in an arbitrary direction. This model is used for the analysis of a 175/70R14 steel-belted radial tyre under inflation loading. The results showed that ignoring the effect of bias cord angle (e.g., belt angle) on the elastic properties of the cord-rubber composite give rise to prediction of inaccurate tyre deformed shape. The accuracy and validity of the model has also been verified by the comparison of the value of the computed tyre crown displacement with available experimental results.